We consider the applications the Parker hydrodynamic approximation to stationary spherically symmetric plasma expansion from the Sun into a vacuum. We present a system of four equations including the continuity, ion motion, local electron equilibrium equations and equation of quasineutrality of stationary spherically symmetric plasma flux under a homogeneous temperature of components with consideration for the gravitational and electric fields. Analytical expressions for the relationship between the electric field and electron density and the distance to the Sun centre are derived. The positive charge of the Sun is assessed. Our results are used to the solar wind.